With rapid development of display technology in recent years, a touch display device capable of receiving information inputs, in which a touch device is mounted on a display device such as a Liquid Crystal Display (LCD) device or a touch device is integrated with a display device and various button images and the like are displayed on the display device in place of conventional mechanical buttons, arouses attentions. Because the touch display device does not need input devices such as a keyboard, a mouse and a keypad, the touch display device is increasingly applied to portable terminals such as mobile phones.
For a touch display panel, scanning circuits are generally disposed at the periphery of the display panel and connected typically in three manners, a double-side scanning manner in which the same drive electrode is driven for scanning by individual wirings from two sides of the display panel, a single-side scanning manner in which each drive electrode is driven for scanning by an individual wiring on one side of the display panel, and a double-side interleaved scanning manner in which drive electrodes are respectively driven for scanning by individual wirings on two sides of the display panel. In the case of the double-side scanning manner, identical scanning circuits are required on two sides of the display panel to drive the same drive electrode for synchronous scanning, as a result, the whole touch display panel cannot normally complete scanning if only the scanning circuit on one side of the display panel fails. In the case of the single-side scanning manner or the double-side interleaved scanning manner, because a touch drive signal/VCOM signal is supplied only from a single side of the display panel, a voltage drop is caused at the distal end of the drive electrode, thereby negatively affecting the scanning of the touch display panel and normal display of the LCD device.